Centrifugal mold apparatus



June 27, 1950 E. R. oLsEN Erm.

CENTRIFUGAL MOLD APPARATUS Filed Aug. 17, 1946 6 www 3 N Mmfmm /MMMQ TA 00 www [FU its outer edges to the cylindrical jacket l.

Patented yJune 27, 1950 cEN'rRmUGAL Mom APPARATUS ltrncst B.. Olsen, Rudolph F. Flora,vand Clifford J.

Lonnee, Muskegon, Mich., signora to Hastings Manufacturing Company, Hastings, Mich.

Application August 17, 1946, Serial No. 691,348,

This invention relates to improvements in cen.

trifugal mold apparatus.

The principal objects of the invention are:

First, to provide 'means for uniformly cooling a casting in a centrifugal mold.

Second, to provide improved centrifugal mold-l ing apparatusn which the castings are formed against a liner of sheet asbestos removable with the casting so that the casting is easily removable and will have a machinable surface without heat treating.

s claims. (ci. zar-113,5)

Extending through the hollow shaft 8 is a pipe 9 provided with a sliding connection at III to the Ushap^d water supply pipe II. The pipes 9 and II are arranged to supply cooling water to the forward end of the annular-space between y Third, to provide centrifugal molding apparatusI I with a permanent mold arranged lto permit the escape of gases formed vin the casting operation.

Fourth', to provide centrifugal molding app'a- Aratus arranged to support a preformed renewable,-

Other objects and advantages relating. to de,

tails and economies of the invention will be apparent from the following descriptions. The invention is further pointed out in the claims.

'The drawings, of which there is one sheet, illustrate a preferred form of casting apparatus.- and two modified forms of molds adapted to be used therein.

Fig. '1 is a longitudinal cross sectional view, partially broken away, through the rotatable head of the casting apparatus.

Fig. 2 is a fragmentary cross sectional view taken along the plane of the broken line 2-2 in Fig. 1.

Fig. 3- is a perspective view of the asbestos liner shown in Figs. 1 and 2. a

Fig. 4 is an enlarged fragmentary elevational view illustrating in greater detail, the permanent mold shown in Figs. 1 and 2. v

Fig. 5 is a fragmentary perspective view showing a first modified form of mold.`

Fig. 6 is a fragmentary elevational view showing a second modiiled form'of mold.

The reference character I indicates generally the rotatable head of a centrifugal casting apparatus which consists vof a cylindrical mold container member 2 mounted at its forward end on a front plate l and closed at its rear end by the disk l. The front plate I defines a circular aperture opening into the containerand Is secured at The rear end of the jacket' is secured to the circular face plate i which is mounted onthe sleeve 1. 'I'he sleeve 1 is secured to the hollow shaft I which is arranged to be rotated at high speed by suitable machinery which is not shown.

the jacket 5 and the mold container 2. The water is removedfrom the jacket by owing out through the hollow shaft 8 as indicated by the arrows in Fig. 1.

Positioned within the container 2 is a permanent metal mold member I2 which is Vgenerally cylindrical in outside diameter and arranged to fit tightly within the container 2. The mold I2 may be split longitudinally as at I3, see Figs. 2 and 4, to facilitate its installation in the container. The inside surface-of the mold may be of cylindrical shape or in the case where it is used for casting out-of-round piston ring stock, it may be formed slightly out-of-'round or attened 'along one of its elements. The thickness of the mold I2 may be varied, depending upon 'the outside diameter of the casting desired. A

series of small radially extendingbores I 4 are formed in the walls of the mold and disposed spirally around the mold. The outer surface of the mold is formed with a spiral'grooveI I5 which communicates with the ends of the bores i4 as ismost clearly shown in Fig. 4.' Ths a vent is formed from the interior of the moldallalong the inner surface of the container tdltlieforward end of the mold. The vent is necessary 'to remove gases formed in the casting 'operation aswill be explained presently. 1 V Positioned within the mold I2 isa mold wall liner I6 formed preferably of a'preformed bendable sheet of asbestos rolled into tubular shape and inserted in the mold. The'rolled liner thus formed, covers the inner ends of the bores I4 and the slot I3 and itself forms a longitudinal slot .I1 which is preferably made as small as possible by cutting the asbestos sheet to a length approximately equal tothe inner circumferenceof the mold. The adjacent edges of the liner are not connected andthe liner is free to t or conform to the mold cavity wall.

The outer surface of the' liner may be Toughened as at I8 by embossing or finishing the sheet on a rough surface. This leaves a series of small depressions between the mold and the liner facilitating the escape of gases resulting from the casting operation. V

Details of the formation of this form of liner are 'more particularly show n and claimed in our `29, 1949. However, liners havingsmooth outer ing of the starch or other binder and moisture in the asbestos tube, may collect in the small depressions in the outside of theliner and escape through the radial bores I4 to the spiral groove I5 through which they may escape to the front of the mold. 'I'he centrifugal action of the molten metal presses the liner closely against the mold cavity wall. The cooling fluid may be supplied during a part or all of the pouring period. The continued supply of cooling fluid to the jacket determines the rate of cooling ofthe casting and consequently, the grain structure of the metal. When the casting has solidied, it may be removed from the mold along with the liner which adheres to the casting and which slides easily from the mold and greatly facilitates removal of the casting. The asbestos liner not only prevents chilling of the casting but protects the permanent mold I2 from the direct action of the hot metal. The mold is thus clean and immediately ready for another casting operation. Each liner II is easily installed by rolling it into a small tube and letting it unroll into contact with the mold I2. The liner can further be seated by running a smooth plug or expander into the liner. As stated, the centrifugal force of the metal also acts to seat the liner.

Fig. 5 illustrates a modii'led form of tubular mold which is provided with a series of radially extending bores 2| which are disposed in a series of parallel lines and connected at their outer ends with the longitudinally extending grooves 22. Gases escaping through the bores 2| will be discharged through the grooves to the end of the mold.

In the modified form of mold shown in Fig. 6.

the mold 23 is provided with a series of radial` bores 24 as in the other forms of molds shown.

.but instead of connecting grooves, the outer surface of the mold has been knurled. forming a I0 series of crossing grooves 25 which communi--V cate with the several bores 24 and permit the escape of gases to the end of the mold.

Centrifugal casting of sleeves vand tubular members is greatly simpllned by our method since the use of sheet asbestos liners results in uniform machinable surfaces on the castings without heat treatment.v Further, the liners protect and prolong the life of the molds. The vents in the molds prevent the liners from bulging inwardly out of shape and the large volume of cooling water space in the jacket assures an even, rapid cooling rate for the casting. Thus, the

'output of a centrifugal casting machine is both increased and improved.

In the claims the term "heat resistant material" should be construed and interpreted to mean any material having heat resistant and in- What we claim as new and desire to secure by Letters Patent, is:

l. Centrifugal casting apparatus for castingl tubular ferrous members comprising. a rotatable cooled jacket, a tubular mold container with a closed inner end positioned within and carried by said Jacket, a tubular permanent mold member removably positioned in said container and having a plurality of small bores formed comlo pletely through and distributed over the wall of said mold member, said mold member being split longitudinally to facilitate assembly in said container, the outer surface of said mold member and the inner surface of said container being l5 congured and cooperating to form a spiral groove therebetween connecting with the outer ends of said bores and the open end of said container, and a liner of preformed springable sheet material having the heat resistant and insulat- 90 ing properties of sheet asbestos and rolled into tubular form and positioned against the'inner wall of said mold member with the adjacent edges of the sheet unattached.

2. Centrifugal casting apparatus for casting 25 tubular ferrous objects comprising, a. rotatable cooled cylindrical container having a. closed inner end, a tubular mold member positioned in said container and in heat transfer contact therewith, said mold member having a plurality of vent holes formed completely through and distributed over the wall thereof, the adjacent surfaces of said mold member and said container being configured and cooperating to form passages therebetween communicating between the outer ends of said vent holes and the open end of said con tainer, and a bendable liner of preformed sheet material having heat resistant and insulating properties positioned in said mold member in facing, and substantially covering relationship U with the inner surface of said mold member and with the adjacent edges of the sheet unattached.

` 3. Centrifugal -casting apparatus for casting tubular ferrous elements comprising, a rotatable cooled cylindrical container having a, closed inner l end, a. tubular mold member positioned in said grooved to cooperate with the inner wall of said container to form a vent passage between said container and said mold member and connecting Il seid vents with the open end of said container,

and a liner positioned against the inner wall of said mold member in unattached substantially covering facing relationship therewith, said liner being formed from a, preformed sheet of resilient oo heat resistant material and having its adjacent edges unattached, the outer surface of said liner being roughened to form a plurality of fine grooves between said liner and said mold member.

4. Centrifugal casting apparatus for .casting r tubular ferrous members comprising. a rotatable cooled jacket, a cylindrical mold container with a closed inner end positioned within said jacket, a tubular permanent mold member positioned in said container with the adjacent walls of said container and mold member in .abutting heat transfer relationship, said mold member having a plurality of small vents formed completely through and distributed over the wall thereof, the outer surface of said mold member having 1I a series of longitudinal grooves formed therein and connecting the outer ends of said vents with the open end of said container, and a resilient liner of preformed sheet material having the heat resistant .and insulating properties of sheet asbestos rolled into tubular form and positioned in unattached substantially covering facing relationship against the inner wall of said mold member with the adjacent edges of said liner unattached.

5. Centrifugal casting apparatus for casting tubular ferrous objects comprising, a rotatable cooled cylindrical container having a closed inner end, a tubular permanent mold member positioned in said container with the adjacent surfaces of said container and mold member in contacting heat 'transfer relationship, the wall of said mold member having a plurality of vent holes formed completely therethrough and distributed thereover, the outer surface of said mold member being knurled to form grooves communicatng with the outer ends of said vent holes wall having venting passages formed therein and open to the space around said mold, and a preformed bendable liner of sheet asbestos disposed within and substantially covering said mold cavity wall in radially supported relation thereto, the liner being unattached to the mold cavity Wall and having its adjacent edges unattached whereby said liner may extend and contract radially with thermal expansion and contraction of said mold member.

ERNEST R. OLSEN.

RUDOLPH F. FLORA.

CLIFFORD J. LONNEE.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 359,483 Whitley Mar. 15, 1887 652,756 Deming July 3, 1900 661,143 Grasser Nov. 6, 1900 665,865 Baker Jan. l5, 1901 1,027,585 Bennett May 28, 1912 1,249,101 Jacobs Dec. 4, 1917 1,320,910 Perry Nov. 4, 1919 1,356,712 Hachmann Oct. 26, 1920 1,441,885 Sanford Jan. 9, 1923 2,093,286 Millspaugh Sept. 14, 1937 2,110,426 Schwartz et al. Mar. 8, 1938 2,130,726 Ardelt Sept. 20, 1938 2,266,831 Tegarty Dec. 23, 1941 

